Answer
Run a PL/SQL diagnostic block that loops through every LU name in DICTIONARY_SYS_TAB, calling Dictionary_SYS.Get_Base_Package on each one inside an exception handler that prints out any LU name that raises an error — this surfaces exactly which specific LU(s) are failing an internal dictionary lookup, which is what actually causes Query Builder to hang. For each LU name that gets flagged this way, check that table's COMMENT ON TABLE metadata (which encodes LU=...^PROMPT=...^MODULE=...^) — the LU name value embedded in that comment needs to exactly match the LU's real, properly-cased name (e.g. AgrResrceEmpLoadCapacity, not the raw uppercase table name) for Query Builder's dictionary lookups to succeed; correct any mismatched comments found. If the diagnostic block doesn't surface any failing LU at all, instead run BEGIN Dictionary_SYS.Rebuild_Dictionary_Storage_(0,'FULL'); COMMIT; END;, then refresh all server caches.